Research: The basic research presently being conducted and to be continued involves the investigation of the clotting mechanisms of patients with sickle cell disease during and in between crises. Further proposed basic research will be centered around evaluation of body defenses in sickle cell anemia particularly those related to the complement system and/or complement mediated neutrophil functions while well, during crises, and during infections. Concomitantly data will be accumulated regarding infection as an important factor precipitating crisis and a proposed double blind study to evaluate the effectiveness of prophylactic PCN in preventing infection and crises. A significant component of the total project involves an investigation of both educational and social adjustment of children with sickle cell anemia. Treatment: The treatment program is already established and would intend to continue to provide medical services, an out-patient program with surveillance, in-patient and inter-disciplinary services, and non- medical services. Education: Objectives include education of the total community with special effort directed at specific target groups and intensive programs for education of allied health personnel with intended development of various training models and evaluation techniques. Screening and Counseling: This component is to be established as models within existing health care facilities with the intenion that these specific model programs can then readily become part of routine health care delivery.